Process for making parts for the manufacture of high-vacuum tubes and the like



- cathode tubes,

as from the metals,

Patented Sept. 1 925, I

UNITED, STATES AT NT OFFICE.

wrm mmir norm, or mium, ennuamr.

PROCESS FOR MAKING PARTS FOR THE-MANITFACTUBE' OF HIGH-VAC UUM TUBES AND THE No Drawing.

To all whom it may concern:

Be it known that I, WILHELM Roms, a citizen of Germany, and resident of Hanan, Germany, have invented new and useful l Processes for Making Parts for the Manufacture of High-Vacuum Tubes and the like (for which I have filed application in Germany April 18, 1918), of which the following is, a specification;

7 It is' known that in making high vacuum tubes, such as, Rontgentubes, incandescent v amplifier and valve .tubes, tubes; for wireless] telegraphy andthe like particular difliculties areencountered in ren- 5 dering the metals contained in such tubes L free from gases; Attempts have been made to remove thegases from thes metals, while evacuating thetubes, by beating them to an excessive degree either directly from outside, or by highly overcharging the tubes. It Was,'however, found impossible to fully free the metals-from gases, even 'by a-protracted treatment, as every fresh rise of temperature causes gas to emerge afresh which then rendered the tubes useless; On the other hand an overheating of'the parts contained in the tube frequently resulted in turning into dust the metals or the like.

The inventorhas described his, British:

Patent N0. 138,648, dated May 19, 1921, a process invented by himself, by which a sufficient degasification of metals and alloys of metals is obtained by the said metals and I alloys of metals being kept molten for some time under a constant, but very low pressure, or. being remelted several times under the yAppli'cation filed Kay 14,

mm i

1920, Seria1 Ko. '881, 5 19.-

said conditions. Suitable metals and alloys for-this treatment are: magnesium, aluminum, copper, silver, gold, nickel, iron, chromium, platinum, alloys of nickel and iron with manganese, silicon, cobalt, chro mium, molybdenum, tungsten, as well as alloys of nickel with iron and copper. The preferential metals and alloys for use in vacuum tubes are aluminum, copper, nickel, iron, and alloys of nickel with iron, copper,

chromium or manganese, as well as of iron with manganese and chromium.

In doing so it has been found that such metals" or the like, when rolled into sheets or drawn into wire, or when'annealed in the presence of any gases, such as hydrogen, will no more absorb noxious quantities of gases and will therefore give no cause for trouble in making the hereinbefore mentioned tubes.

\Vhat I claimis: i

1. The: process of preparing inner metallic parts for use in high vacuum tubes and the like comprising repeatedly heating the desired metal to a molten condition under a constant but very low pressure, and thereafter, annealing the said metal.

2. The process of preparinginner metallic partsgfor high vacuum tubes and the like comprising repeatedly heating the desired metal to a molten condition under a constant but very low pressure and thereafter mechanically forming sired shape."

this 27 day of- February1920. 1

. v DR. WILHELM ROHN.-

said metal into (19,- a

In testimony, that claim the foregoing as my lDV6Ilt10Il--.I' hayefsigned my name 

